Alkyl vinyl ether polymers containing a lactam functionality

ABSTRACT

The invention relates to polymers containing units of the structure ##STR1## or mixtures of A with more than one of B, B-1 and B-2; wherein R and R 1  are each independently C 1  to C 18  alkyl; 
     R 2  is oxygen, sulfur or --NR 5  --; 
     R 5  is hydrogen or lower alkyl; 
     R 3  is alkylene having from 3 to 6 carbon atoms, optionally mono- or di- substituted with lower alkyl; 
     W is hydrogen --NH 4 , an alkali metal or an alkaline earth metal; 
     Y is alkylene; 
     Z is hydrogen, --NH 4 , an alkali metal or an alkaline earth metal or mixtures thereof; 
     X is lower alkyl, a hydroxy phenyl radical or mixtures thereof; 
     t has a value of from 2 to 8 and 
     m, m&#39;, m&#34; and n independently have a value of from 30 to 3,500 and n represents at least 5 mole percent of the polymeric product. The invention is also related to the synthesis of the above polymers and to their use as superior adhesives which have significantly improved bond strength.

This is a division of application Ser. No. 402,376, filed Sep. 5, 1989.

BACKGROUND OF THE INVENTION

Numerous water soluble polymers and copolymers in commercial use areemployed as adhesive coatings and thickeners for various productsparticularly in the cosmetic and textile finishing arts. However, manyof these products are subject to yellowing and do not provide theadhesive bond strength required for certain applications. Theinterpolymer of alkyl vinyl ether and maleic anhydride in approximatelya 1:1 proportion has excellent film forming and adhesive properties.However, the polymer is subject to embritlement under certain conditionsover an extended period of time. Also, this polymer possesses onlymoderate bond strength when applied to a substrate.

Accordingly, it is an object of this invention to overcome the abovedeficiencies with polymer having a unique structure and superiorproperties.

Another object is to enhance the bond strength of alkyl vinylether/maleic anhydride copolymers by certain modifications which promotehydrogen bonding.

Another object of this invention is to provide polymers capable offorming clear, non-yellowing films characterized by superior adhesivestrength which can be employed in pharmaceutical, cosmetic and textilefinishing applications.

Still another object of the invention is to provide an economical andcommercially feasible method for the preparation of said polymers.

These and other objects of the invention will become apparent from thefollowing description and disclosure.

THE INVENTION

In accordance with this invention there is provided a novel alkyl vinylether polymer containing a lactam moiety chemically bonded to thepolymeric backbone and having repeating units of the structures:##STR2## or mixtures thereof with unit A wherein R and R¹ are eachindependently C₁ to C₁₈ alkyl;

R² is oxygen, sulfur or --NR⁵ --;

R⁵ is hydrogen or lower alkyl;

R³ is alkylene having from 3 to 6 carbon atoms, optionally mono- or di-substituted with lower alkyl;

W is hydrogen, --NH₄, an alkali metal or an alkaline earth metal;

Y is alkylene of linear, branched or cyclic structure;

Z is hydrogen, --NH₄, an alkali metal or an alkaline earth metal;

X is a hydroxy phenyl radical, lower alkyl or mixtures thereof;

t has a value of from 2 to 8 and

m, m', m" and n independently have a value of from 30 to 3,500 and nrepresents at least 5 mole percent of the polymer.

The polymers of this invention can have molecular weights up to about1,000,000; although molecular weights between about 35,000 and about250,000 are preferred. Also preferred are those polymers wherein R³ ispropylene or butylene and n has a value of from about 100 to about 400.

As illustrated above, the lactam is not blended with the interpolymerbut is instead chemically bonded to the copolymeric backbone whichaccounts for the unusually high adhesive strength of the presentproducts as well as their solubility characteristics.

The polymers of the present invention are water soluble and form clearcolorless films which are not subject to yellowing over extendedperiods. The polymers of higher molecular weight, e.g. higher than75,000, are excellent thickening and gelling agents for manycompositions employed in the fields of cosmetics and commercialdetergents. The lactam moiety of the polymer contributes conditioningproperties when applied to keratinous substrates and have an enduringsoftening effect. In pharmacetucial and agricultural applications, thelow toxicity of the present products recommends their use as complexingagents to provide controlled release of active components. In additionto the above enumerated benefits for drug, cosmetic and agriculturaldelivery systems, it is found that the present polymer inhibits scaledeposits in industrial equipment and piping. While the present polymersare readily soluble in water, they resist attack by many commercialsolvents including ethanol, ethyl acetate, tetrahydrofuran, ketones suchas acetone, methylethyl ketone and alkanes such as hexane. This propertyis particularly unexpected since both the lactam and the alkyl vinylether/maleic anhydride copolymers are soluble in these solvents. Othergeneral uses include their applications as solubilizers and dispersingagents and will become apparent from this disclosure.

The present polymeric units are randomly or alternatingly disposed;although the polymer may also contain portions of block structure, aswhen unit A contains a block-like structure. In general, the presentcopolymers contain at least 5 wt. %, preferably at least 10 wt. %, ofthe lactam containing unit, and most preferably between about 20% andabout 60% by weight of said lactam moiety.

Copolymer A of the present invention, where Z is hydrogen, can beprepared by reacting the alkyl vinyl ether-maleic anhydride co-polymer##STR3## with a lactam of the formula ##STR4## wherein R⁴ is --OH, --SH,--NH₂ or --NHR⁵ and R⁵ is lower alkyl. This reaction is carried out at atemperature of from about 20° C. to about 100° C. for a period of fromabout 20 minutes to about 5 hours under between about 0 and about 50psig.

Generally, it is recommended that the alkyl vinyl ether/maleic anhydridecopolymer, for example GANTREZ® AN, be dissolved in an inert solventsuch as for example, methylethyl ketone, ethyl acetate, tetrahydrofuran,acetone, chloroform, etc. and mixtures thereof to provide a solutioncontaining between about 6 and about 30% by weight, preferably betweenabout 15 and about 25% by weight of the copolymer. The lactam isgradually added to this solution either as a solid or as a liquid;although, when the lactam is a solid, it is recommended that it bepredissolved in an inert solvent, preferably in the same solventemployed for the copolymer solution. The reaction is carried out in anoxygen-free atmosphere with agitation.

To obtain the corresponding salt of copolymer A, the above half acidproduct is reacted under similar conditions with a salt forming alkalimetal or alkaline earth metal compound such as an oxide, hydroxide orcarbonate of said metals or with ammonium hydroxide. Details of thesereactions are more completely described in our copending patentapplication FDN-1772.

On completion of the reaction a solid product precipitate is separatedfrom the reaction mixture by filtration, after which it is washed withthe selected solvent and dried for solvent removal. The drying step canbe carried out under vacuum or the product can be air dried at roomtemperature or slightly elevated temperature up to about 60° C. for aperiod of up to about 20 hours.

Polymers with unit A such as A with at least one of B, B-1 or B-2 can besynthesized by several different reactions.

Procedure I

To obtain the product containing a mixture of A and B units, an excessof reactant C is employed in the above described reaction of C+D. Theexcess amount of C depends on the proportion of maleic anhydride unitsdesired in the product. By way of illustration, the mole ratio ofreactant C to reactant D can vary between about 1:0.1 to about 1:0.9,preferably from about 1:0.3 to about 1:0.7 depending upon the amount ofanhydride units to be incorporated with the copolymer in theinterpolymeric product.

Procedure II

To obtain the polymer containing A and B-1 or A, B and B-1 units, theabove maleic anhydride containing polymer of procedure I is hydrolyzedcompletely or in part to the corresponding maleic acid. This reaction isalso effected under the process conditions given above except that theamount of water or steam or the duration of the reaction can be variedin accordance with the amount of dicarboxylic acid groups desired in theproduct.

Procedure III

Polymers containing A and B-2 salt or A, B-1 and B-2 salt units areprepared by reacting the above polymer of Procedure II in the completelyhydrolyzed state with an inorganic salt forming compound such as analkali metal, an alkaline earth metal, ammonium or zinc compound such asa hydroxide an oxide, a carbonate and the like. Specific examplesinclude NH₄ OH, NaOh, KOH, Mg(OH)₂, Zn(OH)₂, ZnO, CaCO₃, K₂ CO₃, Na₂CO₃, etc. Depending upon the amount of salt forming reactant employed,the acid groups of the resulting polymer are completely converted tosalt or only partially converted so that the product contains units ofB-1.

Polymeric compositions of units A+B+B-1 +B-2 salt or A+B+B-2 salt arealso obtainable by reacting the partially hydrolyzed polymer ofprocedure II with the salt forming compound under similar conditions.

Procedure IV

The metal or ammonium salt polymers of units A+B+B-2 can also beprepared by directly reacting the non-hydrolyzed polymer containingunits A+B of procedure I with the inorganic salt forming compound undersimilar salt forming conditions.

Procedure V

The ester containing polymer of A+B-2 ester or A +B-2 ester units issynthesized by reacting the interpolymeric product of Procedure I withan alcohol or with a hydroxy phenyl reactant, such as a C₁ to C₄alkanol, phenol, hydroquinol, para hydroxy benzoates etc. Again, partialor complete conversions of the polymeric starting material can beeffected by the amount of hydroxy compound employed.

The reactions of procedures I through V are carred out at a temperatureof from about 20° C. to about 100° C. for a period of from about 20minutes to about 5 hours under between about 0 and abut 100 psig.

Other polymeric combinations of the above defined units will becomeapparent from the foregoing outline of polymer modification procedures.

As stated above the polymers of this invention are water soluble andform abrasion and organic chemical resistant coatings when applied to asubstrate surface. When used in this capacity, coatings of from about0.1 to about 10 mils thickness are recommended.

Having thus generally described the invention, reference is now had tothe accompanying examples which illustrate preferred embodiments of theinvention but which are not to be construed as limiting to the scopethereof as more broadly described above and as set forth in the appendedclaims.

EXAMPLE 1

A 1 liter flask is equipped with a mechanical stirrer, reflux condenser,thermometer, dropping funnel and nitrogen inlet/outlet. Acetone (150 ml)is added to the flask, followed by 78.08 g (0.5 mole) of methyl vinylether/maleic anhydride copolymer (GANTREZ® AN-119, having a molecularweight of about 20,000) and 500 ml of ethyl acetate. The reactionmixture is heated to 60° C. for 1 hour with stirring under a blanket ofnitrogen. 1-(2-Aminoethyl)-2-pyrrolidone (50.4 g, 0.4 mole) is thenadded dropwise to the clear solution over a period of 45 minuteswhereupon a precipitate is formed. The stirring is continued for anadditional 2 hours at 60° C., after which the reaction mixture is cooledto 30° C. and the resulting product precipitate is suction filtered,dried under high vacuum for 8 hours and 124.6 g of product (97% yield)is recovered.

The product conains the following units, ##STR5## is determined by wetanalysis, i.e. titration with 0.1 normal HCl (no free primary amine) and0.1 normal NaOH after hydrolysis with H² O); nitrogen analysis andspectral analysis (IR, 1H and 13CNMR).

Based on these analysis about 78% of the anhydride function in GANTREZ®AN-119 is converted to the half amide/acid form.

EXAMPLE 2

The reaction of Example 1 is repeated except that the amount of1-(2-aminoethyl)-2-pyrrolidone used is 37.8 g (0.3 mole). The productyield is 95.2%. The product contains 40% anhdyride and 60% lactam halfacid units.

EXAMPLE 3

The reaction of Example 1 is repeated except that the amount of1-(2-aminoethyl)-2-pyrrolidone used is 25.2 g (0.2 mole). The productyield is 90.5%, obtained by removing solvent in a rotovap. The productcontains 60% anhydride and 40% lactam half acid units.

EXAMPLE 4

The reaction of Example 1 is repeated except that the amount of1-(2-aminoethyl)-2-pyrrolidone used is 12.6 g (0.1 mole). The productyield is 93.4%, obtained by removing solvent in a rotovap. The productcontains 80% anhydride and 20% of the lactam half acid units.

EXAMPLE 5

The reaction of Example 2 is repeated except that the methyl vinylether/maleic anhydride copolymer GANTREZ® AN-139 having a molecularweight of about 41,000 is substituted for GANTREZ® AN-119. The productyield is 95.8% and the polymer contains 40% anhydride and 60% lactamhalf acid units.

EXAMPLE 6

The reaction of Example 4 is repeated except that the methyl vinylether/maleic anhydride copolymer GANTREZ® AN-149 having a molecularweight of about 50,000 is substituted for GANTREZ® AN-119. The productyield is 97.2% and the polymer contains 40% anhydride and 60% lactamhalf acid units.

EXAMPLE 7

The reaction of Example 2 is repeated except that the methyl vinylether/maleic anhydride copolymer GANTREZ® AN-149 is substituted. Theproduct yield is 98.1% and the polymer contains 40% anhydride and 60%lactam half acid units.

EXAMPLE 8

The reaction of Example 4 is repeated except that the methyl vinylether/maleic anhydride copolymer GANTREZ® AN-149 is substituted. Theproduct is obtained in 93.9% yield and contains 80% anhydride and 20%lactam half acid units.

EXAMPLE 9

The reaction of Example 2 is repeated except that the methyl vinylether/maleic anhydride copolymer GANTREZ® AN-169 having a molecularweight of about 67,000 is substituted. The product is obtained in 98.7%yield and contains 40% anhydride and 60% lactam half acid units.

EXAMPLE 10

The reaction of Example 4 is repeated except that the methyl vinylether/maleic anhydride copolymer GANTREZ® AN-169 is substituted. Theproduct is obtained in 93.6% yield and contains 80% anhydride and 20%lactam half acid units.

EXAMPLE 11

The reaction of Example 2 is repeated except that the lactam used is1-(3-aminopropyl)-2-pyrrolidone. The product is obtained in 96.2% yieldand contains 40% anhydride and 60% lactam half acid units.

EXAMPLE 12

The reaction of Example 2 is repeated, (same molar basis of lactam topolymer) except that the lactam used is 1-(3-aminopropyl)-2-caprolactam.The product is obtained in 94.8% yield and contains 40% anhydride and60% lactam half acid units.

EXAMPLE 13

The reaction of Example 1 is repeated, (same molar basis of lactam topolymer) except that the lactam used is 1-(4-aminobutyl)-2-pyrrolidone.The product is obtained in 95.7% yield and contains 20% anhydride and80% lactam half acid units.

EXAMPLE 14

The reaction of Example 2 is repeated, (same molar basis of lactam topolymer) except that the lactam used is 1-(6-aminohexyl)-2-pyrrolidone.The product is obtained in 96.2% yield and contains 40% anhydride and60% lactam half acid units.

EXAMPLE 15

The reaction of Example 1 is repeated, (same molar basis of lactam topolymer) except that the lactam used is 1-(6-aminohexyl)-2-pyrrolidone.The product is obtained in 98.3% yield and contains 20% anhydride and80% lactam half acid units.

EXAMPLE 16

The reaction of Example 1 is repeated, (same molar basis of lactam topolymer) except that the lactam used is 1-(3-aminopropyl)-2-piperidone.The product is obtained in 97.7% yield and contains 20% anhydride and80% lactam half acid units.

EXAMPLE 17

In a 250 ml beaker, 100 ml water is preheated to about 50° C. andstirred at a speed sufficient to produce a rapidly whirling vortex. Thepolymer (25 g), obtained from Example 2, is added slowly into the vortexso that the powder is rapidly wet and dispersed. The resulting slurry isthen stirred at high speed for about 4 hours until complete solution isachieved. Any water lost by evaporation can be replaced, if desired, atroom temperature with gentle stirring. Such solutions are useful in anadhesive paste or as an adhesive solution. Alternately, water can beremoved by freeze drying or oven drying under vacuum to obtain a freeflowing powder of hydrolyzed polymer containing 40% of the diacid:##STR6## and 60% of the lactam half acid units. Powder products are alsouseful as an adhesive particularly in affixing a device or material to amucous membrane.

EXAMPLE 18

The hydrolyzed polymeric product of Example 17 is neutralized to a pH ofabout 6.5 using a 30% solution of sodium carbonate in water. Thesolution is allowed to stand for 1/2 hour at 40-50° C. to ensurecomplete mass transfer.

The resulting sodium salt solution of the polymer is drum dried andrecovered in 95% yield. The product contains about 80% sodium salt andabout 20% free acid.

EXAMPLE 19

The reaction of Example 18 is repeated except that a 30% slurry ofsodium carbonate and calcium carbonate is employed as the salt formingcompound. The product is about 80% mixed salts of sodium and calcium and20% free acid.

EXAMPLE 20

The reaction of Example 18 is repeated except that a slurry of zincoxide is employed as the salt forming compound. The product containsabout 85% of the zinc salt and about 15% free acid.

EXAMPLE 21

The polymeric product of Example 1 is treated with butanol in a 1:1molar ratio with the anhydride moiety at 50° C. for 3 hours. Theresulting product is collected by filtration and dried. The product isobtained in 95% yield and contains 80% lactam half acid and 20% of thebutyrate of the maleic acid units.

EXAMPLE 22

Films were made on various substrates using a 5% aqueous solution of theproduct from Example 17 and poly(methyl vinyl ether maleic acid). Thefilms were then vacuum dried overnight in an oven at 45° C. The resultsare as reported below.

    ______________________________________                                                                   Poly(methyl                                                                   Vinyl Ether                                        Film Properties                                                                          Product from Ex. 17                                                                           Maleic Acid)                                       ______________________________________                                                   clear, transparent                                                                            slightly hazy,                                                glossy          less glossy                                                   no yellowing after                                                                            slight yellow-                                                2 weeks         ing after 2 weeks                                  Adhesion                                                                      steel      100%            100%                                               Aluminum    95%             85%                                               Polypropylene                                                                            Formation of film                                                                             No film                                            Glass      Formation of film                                                                             No film                                            ______________________________________                                    

What is claimed is:
 1. A liquid phase process for synthesizing a polymercontaining units of ##STR7## wherein R¹ and R are each independently C₁to C₁₈ alkyl; R² is oxygen, sulfur, NH or N(C₁ to C₄ alkyl);R₃ is C₃ plto C₆ alkylene Y is alkylene; W is hydrogen, NH₄, an alkali metal or analkaline earth metal; m, m', and n independently have a value of from 30to 3,500 and t has a value of from 2 to 8wherein said process comprises(a) reacting, in an oxygen-free atmosphere, a C₄ to C₈ lactam having theformula ##STR8## wherein R³, Y and t are as defined and R⁴ is OH, SH,NH₂ or N(C₁ to C₄ alkyl), with a molar excess of a C₁ to C₁₈ alkyl vinylether-maleic anhydride copolymer at a temperature of between about 20°C. and about 100° C. under from about 0 to about 100 psig, recovering afirst polymer comprised of units having the formulae ##STR9## (b)subjecting said first polymer to hydrolysis to convert at least aportion of the anhydride units to diacid units having the formula##STR10## as a second polymer and the product of the process.
 2. Theprocess of claim 1 wherein the alkyl vinyl ether moiety is methyl vinylether.
 3. The process of claim 1 wherein the alkyl vinyl ether moiety isethyl vinyl ether.
 4. The process of claim 1 wherein the alkyl vinylether moiety is butyl vinyl ether.
 5. The process of claim 1 wherein thelactam is a pyrrolidone.
 6. The process of claim 1 wherein R⁴ of thelactam is OH.
 7. The process of claim 1 wherein R⁴ of the lactam is NH₂.